a. Field of the Invention
This invention relates to 21,23-epoxy-23-methoxy-24-nor-5.beta. ,14.beta.-chola-20,22-diene-22-carbonitriles, to 22-cyano-5.beta.-card-20(22)-enolide intermediates and to methods of preparing and using these compounds. the compounds of this invention as well as the 22-cyanocardenolide intermediates show cardiotonic activity in mammals and this property renders them useful as cardiotonic agents.
B. Prior Art
The only known 21,23-epoxy-24-nor-5.beta.,14.beta.-chola-20,22-dienes appear to be the 17-[3-furyl] -5.beta.,14.beta.-androstanes described in Canadian Pat. No. 803,506, issued Jan. 17, 1969.
On the other hand, concerning the 22-cyano-5.beta.-card-20(22)-erolide intermediates, some 22-substituted cardenolides are known besides the naturally-occurring glycosides and aglycones (see for example in German Pat. Nos. 1,027,668, 1,920,176, 1,920,394, 2,000,338, 2,001,364 and 2,015,850 and also in Dutch Pat. No. 72-12308 and Belgian Pat. No. 751,768.